Lifebreath METRO 120D

Questions and Answers

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kimliuAug 4, 2025
How to improve poor airflows in Lifebreath Heating System?
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  Hannah BarronAug 5, 2025
  Poor airflow in your Lifebreath Heating System can stem from several causes. Begin by cleaning any obstructions from the exterior hoods or vents. Check and clean the filters. Ensure the core is free from obstructions. Open any closed or blocked house grilles and adjust dampers if installed. Have an electrician check the power supply voltage. Verify that the ductwork isn't restricting the HRV/ERV. Adjust the speed control setting to increase the HRV/ERV speed. If the issue persists, have a contractor balance the HRV/ERV.
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Kayla JimenezAug 11, 2025
Why does supply air feel cold from Lifebreath Heating System?
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  gordonmelissaAug 11, 2025
  If the supply air from your Lifebreath Heating System feels cold, it could be due to the location of the supply grilles. Relocate the grilles high on the walls or under the baseboards, or install ceiling-mounted diffusers or grilles to avoid direct airflow on occupants. If the outdoor temperature is extremely cold, turn down the HRV/ERV supply speed. Consider using a small duct heater (1 kW) to temper the supply air.
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Alicia MacdonaldAug 16, 2025
How to fix low humidity levels in Lifebreath Heating System?
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  gibbsjacquelineAug 16, 2025
  Low humidity levels in your home can be adjusted by setting the dehumidistat higher. Try decreasing the HRV/ERV blower speed. Consider adding humidity with humidifiers, and have a contractor balance the HRV/ERV airflows.
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nathanfoleyAug 22, 2025
What to do if condensation or ice buildup in insulated duct to the outside of Lifebreath Heating System?
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  Derek GuerreroAug 22, 2025
  If you notice condensation or ice buildup in the insulated duct of your Lifebreath Heating System, ensure that the vapor barrier around the insulated duct is complete by taping and sealing all joints. Also, tape any holes or tears in the outer duct covering, ensuring that the vapor barrier is completely sealed.
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Taylor HinesAug 28, 2025
What to do if dehumidistat is not operating in Lifebreath Heating System?
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  Thomas HernandezAug 28, 2025
  If your Lifebreath Heating System's dehumidistat isn't operating, first check if the outdoor temperature is above 15°C (59°F), as the dehumidistat functions normally above this temperature. Verify that the low voltage connection is correct and that the correct terminals have been used. Inspect the external wiring for shorts caused by staples or nails. Finally, ensure the dehumidistat is set to the desired setting.

Summary

Pre-Installation Notes

General Installation Notes

General guidance for unit installation, including product change notifications.

Electrical Safety Precautions

Essential electrical safety guidelines and precautions for installation.

System Compatibility and Drainage

Electrical Shock and Service Safety

Critical warnings about electrical shock and safe servicing practices.

Simplified Installation (Return;Return Method)

Partially Dedicated System Installation

Fully Dedicated System Installation

Installation Warnings

Specific warnings related to jurisdiction and applications.

Mounting the METRO HRV;ERVs

Mounting Caution

Important warning against drilling additional holes in the unit.

Drain Connection (HRVs Only)

Drainage Precautions

Cautions regarding temperature, slope, and secondary pans for condensate.

Lifebreath Weather Hoods

Weather Hood Placement Requirements

Guidelines for correct placement of weather hoods regarding intake and exhaust.

Lifebreath Dual Hood Installation

Installation Cautions and Compliance

Notes on sealant, insulation, and compliance with local building codes.

Main Control Installation (99-DXPL02)

Main Control Installation (99-BC02;3;4)

Installation Steps

Detailed steps for mounting and wiring the 99-BC02/3/4 main control.

Interlocking HRV;ERV with Air Handler;Furnace

Interconnection Procedure

How to wire the HRV/ERV to the furnace/air handler for continuous operation.

Wireless Timer Operation and Installation

Wireless Timer Pairing and Unpairing

Balancing Airflows

Pressure Considerations

Effects of positive and negative house pressure on building integrity.

Balancing Airflows (Continued)

Determining Airflow (CFM)

Method for calculating airflow in CFM using velocity pressure readings.

Balancing Airflows with Pitot Tube

Pitot Tube Balancing Procedure

Step-by-step guide for balancing airflows using a pitot tube.

Troubleshooting Common Issues

Airflow Problems

Solutions for symptoms related to poor airflow, plugged filters, or blocked dampers.

High Humidity and Condensation

Addressing high humidity and window condensation with HRV/ERV settings.

Troubleshooting (Continued)

Low Humidity and Frosting Issues

Solutions for low humidity, duct frosting, and defrost system malfunction.

This document is an installation manual for Lifebreath METRO Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs), designed for indoor air systems. The manual covers various models including METRO 120D, METRO 120F, METRO 120D-ECM, METRO 120F-ECM, METRO 120 ERV, METRO 120ERVD, METRO 120 ERV-ECM, and METRO 120 ERVD-ECM.

Function Description

Lifebreath HRVs and ERVs are ventilation systems designed to improve indoor air quality by exchanging stale indoor air with fresh outdoor air. HRVs recover heat from the exhaust air and transfer it to the incoming fresh air, while ERVs recover both heat and moisture. This process helps maintain comfortable indoor temperatures and humidity levels while minimizing energy loss. The systems are intended for residential use and can be integrated with existing HVAC systems or operate as fully dedicated ventilation systems.

The core function involves two separate airstreams: one bringing fresh air into the house and another exhausting stale air from the house. Inside the unit, a heat/energy exchange core facilitates the transfer of heat (and moisture in ERVs) between these two airstreams without mixing them. This ensures that the energy used to heat or cool the indoor air is partially recovered, reducing the energy burden on the main heating or cooling system.

The manual outlines three primary installation methods:

Simplified Installation (Return/Return Method): This method integrates the HRV/ERV with the existing forced air furnace or air handler's return ductwork. It requires the furnace blower to run continuously or be interlocked with the HRV/ERV operation to ensure proper air distribution. Backdraft dampers are recommended to prevent outdoor air from entering the unit when it's in standby.
Partially Dedicated System Installation: In this setup, stale air is exhausted from specific areas of the home (e.g., bathrooms, kitchens) through dedicated ductwork, while fresh air is supplied to the return duct of the furnace. This method also requires the furnace blower to operate in conjunction with the HRV/ERV.
Fully Dedicated System Installation: This is the most comprehensive method, involving separate ductwork for both stale air exhaust from various parts of the home and fresh air supply to main living areas. This system operates independently of the main HVAC system's ductwork, though the HRV/ERV still needs to be balanced.

Important Technical Specifications

Electrical Requirements: The units operate on a standard 120 VAC electrical outlet with ground. A separate 15 A/120 V circuit is recommended.
Control Wiring: Low voltage control wiring is used for main controls, timers, and other accessories. The manual specifies 3-wire, 20-gauge (min.) wire, up to 100 ft in length (max.).
Duct Sizes: The manual references common duct sizes for grilles and fittings, including 4, 5, 6, and 8 inches. The Lifebreath Dual Hood requires a 6-inch opening for both intake and exhaust and supports a maximum airflow of 140 cfm.
Mounting: The units are designed to be mounted in a heated space, with a minimum clearance of 25 inches (635 mm) at the front for service access. Four straps are provided for hanging from basement floor joists. Attic installations are generally not recommended unless the unit is in a conditioned space.
Condensate Drainage (HRVs only): HRVs produce condensate during defrost cycles, requiring a 4-position drain spout and a 1/2-inch drain hose (not included). The unit must be installed level to ensure proper drainage, and all condensate lines must be in a space maintained above freezing.
Weather Hoods: Fixed covered weather hoods include a 1/4-inch (6 mm) mesh bird screen. Proper sealing and insulation of ductwork connected to weather hoods are crucial. Intake hoods should be located upstream from exhaust outlets and away from potential contaminants.
ECM Motors (METRO-ECM models): These models feature Electronically Commutated Motors, allowing for adjustable fan speeds. The airflow can be fine-tuned via buttons on the ECM circuit board.
Airflow Balancing: Critical for optimal performance, balancing ensures equal amounts of air are supplied and exhausted. This is typically done on high speed with the furnace blower on (if applicable). A digital manometer with a pitot tube attachment is recommended for accurate airflow measurement.

Usage Features

Main Controls:
- 99-DXPL02: A surface-mounted digital main control that allows users to select fan speeds. It supports a "standby" mode where timers can initiate high-speed ventilation.
- 99-BC02/3/4: These controls can be flush-mounted in an electrical switch box or surface-mounted. They also manage fan speeds and can be configured for "standby" mode.
Timers:
- 20/40/60 Minute Timer (99-DET01): A wired timer that connects to the main control terminals, allowing for timed high-speed ventilation.
- Mechanical Timers (99-101): A 2-wire "dry contact" timer that initiates high-speed ventilation when activated.
- Wireless 20/40/60 Minute Timer (99-DET02): A wireless timer that needs to be "paired" with the digital main control (99-DXPL02, 99-BC02/3/4). It provides flexible placement without requiring control wiring.
Repeaters (99-RX02): Used to extend the range of wireless timers. These plug directly into a 120V power outlet and must be paired with the main control. An LED indicator shows connection strength.
Adjustable High Speed Settings: DIP switches on the circuit board allow installers to select between three different high-speed settings (Hi1, Hi2, Hi3) to match specific ventilation requirements. The factory setting is Hi3.
Recirculation Functionality: Some units offer a recirculation option, controlled by a DIP switch, which allows the unit to circulate indoor air without bringing in fresh outdoor air.
Grilles and Fittings:
- Kitchen Grille (Part# 99-10-002): Includes a removable grease filter, often required by building codes.
- TechGrille (Part# 99-EAG4/5/6/8): Round, fully adjustable grilles for quiet air distribution in various sizes.
- Quick Mount Fitting (Part# 99-QM6): A rough-in fitting for pre-drywall installation, nailed to a stud.
- Stack Head Elbow (Part# 99-WF 4/6): Ideal for running ducting through 2x4 studded walls, also for pre-drywall installation.
- Terminator Fitting (Part# 99-TM 4/5/6): A versatile rough-in fitting for pre-drywall installation, adaptable to rigid and flex ducting, providing strong attachment for grilles.
- Suspended Ceiling Fitting (Part# 99-CF6): Designed for ceiling tiles or finished drywall, allowing for easy installation and retention.

Maintenance Features

Filter and Core Access: The unit's design provides easy access to air filters and the heat/energy recovery core for cleaning and servicing. A minimum of 25 inches (635 mm) clearance is required at the front of the access door.
Weather Hood Cleaning: Weather hoods are hinged to allow easy access for cleaning the mesh screen, preventing blockages from foreign objects.
Troubleshooting Guide: The manual includes a comprehensive troubleshooting table to diagnose common issues such as poor airflows, cold supply air, dehumidistat malfunction, high humidity, frosting, condensation, excess water in the unit, and excessive vibration. This guide helps identify causes and provides solutions, often involving cleaning filters/cores, adjusting settings, checking wiring, or contacting a qualified contractor.
ECM Motor Adjustment: The ECM motors can be adjusted to fine-tune airflow, which can be part of routine maintenance or re-balancing.
Balancing Procedures: Regular airflow balancing is crucial for maintaining efficiency and proper defrosting. The manual provides detailed steps for balancing using a pitot tube and digital manometer.